[HRCT findings of pulmonary Mycobacterium avium complex: a comparison with tuberculosis].

Computed tomographic (CT) findings of 70 patients with Mycobacterium avium complex (MAC) disease were analyzed by two chest radiologists and compared with those of 37 patients with Mycobacterium tuberculosis infection. Common CT findings in patients with MAC, included bronchiectasis (97%), small nodules (89%), parenchymal distortion (60%), bronchial wall thickening (56%), consolidation (50%) and cavity formation (49%) and small nodules (86%), bronchiectasis (70%), consolidation (57%) and bronchial wall thickening (51%) in patients with Mycobacterium tuberculosis. Bronchiectasis and parenchymal distortion were significant in patients with MAC compared with Mycobacterium tuberculosis patients. Bronchiectasis involving the RUL, RML, lingula and LLL and small nodules involving the RML were often seen in patients with MAC. Both bronchiectasis and small nodules were commonly observed in multiple lobes in both types of patients. Cavities in MAC infection tended to be thin and smooth walled, and less commonly associated with consolidation. We conclude that CT findings of MAC infection were characterized by widely distributed bronchiectasis and small nodules and/or cavities with thin, smooth walls. These CT findings are one of the keys in differentiating MAC from Mycobacterium tuberculosis.